Electrical connector



y 50 E. w. VARNUM 2,506,979

ELECTRICAL CONNECTOR Filed Feb. 20, 1947 ATTORNEY Patented May 9, 1950 UNITED STATES PATENT OFFICE ELECTRICAL CONNECTOR Application February 20, 1947, Serial No. 729,743

2 Claims.

This invention relates to an electrical connector.

In general, the object of the invention is to provide a novel and improved insulated electrical connector wherein the insulation is constructed to cover the connector for its entire length to thereby protect it against accidental short-circuiting, and wherein a portion of the insulation is arranged to be automatically contracted at the forward end of the connector when the electrical connection is being made to a similar or other connector.

With the foregoing general object in view, and such others as may hereinafter appear, the invention consists in the insulated electrical connector and in the insulating member for an electrical connector, hereinafter described and particularly defined in the claims at the end of this specification.

In the drawings illustrating the preferred embodiment of the invention, Fig. 1 is a cross-sectional view of two insulated electrical connectors shown in their operative connected positions; and Fig. 2 is a perspective View of an insulated electrical connector embodying the invention.

In accordance with the present invention an electrical connector of the type comprising an elongated body portion is provided with connecting means at its forward end adapted for coopenation with another electrical connector to effect an electrical connection, and the body portion is provided with an insulating sleeve enclosing the same and normally extending beyond said connecting means of the connector. The insulating sleeve is constructed to contract and expose the aforesaid connecting means when pressure is applied to the end of the sleeve by a, portion of the second connector when the electrical connection is being made.

Referring now to the drawing, which illustrates the preferred embodiment of the invention, Ill, I2 comprise identical connectors, each having a tubular body portion to which the cables I4, I6 are connected in accordance with the usual practice. The body portion of each connector is provided with fingers I3, I so arranged as to permit the two connectors to be moved in a longitudinal direction into telescoping engagement when the connection is made. In the illustrated embodiment Of the invention the fingers comprise semicircular elements of unequal dimensions, one finger I3 having a smaller radius in cross-section than its opposed finger I5, so that when the connection is made the smaller fingers fit within and slidingly engage the larger radius fingers of the terminal members. Provision is also preferably made for locking the fingers in their engaged position, and as herein shown notched portions 26 are provided along the longitudinal edges of adjacent fingers I5, and these notches are brought into engagement by imparting a slight twisting or rotary motion to the connectors, as will be apparent from an inspection of Fig. 1.

While the illustrated form of connecting means is preferably provided at the forward end of each electrical connector, it will be understood that various other forms of connecting means may be employed, including for example that disclosed in the United States patent to Reynolds No. 2,125,816, August 2, 1938.

In accordance with the present invention a metallic connector, having the elongated body portion provided with connecting means at its forward end, is enclosed within an insulating sleeve indicated generally at 20, and having a portion 22 preferably snugly fitting the rear of the body portion and projecting beyond the same, and also preferably having a portion 23 fitting snugly upon the end of the cable connected to the connector. The insulating sleeve is constructed to fit more loosely upon the forward end of the body portion and to normally project a substantial distance beyond the end of the connecting means to thereby fully insulate the connector against accidental short-circuiting when the connector is disconnected. The forward end of the insulating sleeve is also constructed so as to be capable of contraction in a general longitudinal direction upon the application of pressure to the end of the sleeve, thereby enabling the connecting means of the connector to be automatically exposed when the connector is pressed against the second connector with which it is to cooperate in making the electrical connection. As herein shown, the forward end of the sleeve is provided with a plurality of pleats analogous in structure to an accordion pleat so that as illustrated in Fig. 1, when two of the insulated connectors are brought together in the act of making the electrical connection by the telescoping engagement of the fingers I3, I5, as described, the forward ends of the sleeves 20 are brought into abutment so that pressure of one exerted upon the other during the act Of making the connection serves to compress and contract the pleated portion of the sleeves into the position shown in Fig. 1. In practice it is preferred to construct the sleeve of rubber and to mold the entire sleeve into the shape shown in Fig. 2. When the connection is made, the resilience of the contracted portion of the sleeve serves to urge the same against the sleeve upon the second connector, thereby providing a substantially continuous insulation for the connector. When two insulated connectors embodying the present invention are utilized in making the connection, such as is shown in Fig. 1, the resilience of the pleated and compressed portions of the sleeves serves to hold the sleeves firmly in abutment, providing an efiicient insulation for the entire connection. In addition the resilience of the compressed pleated portions of the sleeves assists in holding the notched portions 26 of the connectors in engagement, reducing to a minimum :the 'liability of the connector accidentally becomin disengaged.

While the preferred embodimentof the ,invention has been herein illustrated and-described, it will be understood that the invention may be embodied in other forms within the scope of the following claims.

Having thus described the invention, what is claimed is:

1. An electrical connector comprising an elongated cylindrical metal body portion of substantially uniform diameter throughout its length provided with fingers at its forward end constructed for telescoping engagement with corresponding fingers of a second connector, said metal body portion being provided with and. enclosed within a flexible rubber insulating sleeve snugly fitting said body portion and extending a substantial distance beyond the forward end thereof when disconnected, the forward portion of said sleeve being provided with a plurality of transverse accordion pleats and capable of substantial longitudinal collapsing movement along said body portion to project said fingers beyond said sleeve when pressure is applied to the end of said sleeve by abutment with a corresponding sleeve of the second connector, the rearmost end of said sleeve being fixed relative to said fingers.

2. An electrical connector comprising an elongated cylindrical metal body portion of substantially uniform diameter throughout its length provided with fingers at its forward end constructed for telescoping engagement with corresponding fingers of a second connector, said metal body portion being provided with and enclosed within a flexible rubber insulating sleeve snugly and fixedly fitting the rear of said body portion and with the forward portion of said sleeve more loosely fitting over and extending a substantial distance beyond the forward end of the body portion when disconnected, the forward portion of said sleeve being provided with a plurality-of transverse accordion pleats and capable of substantial longitudinal collapsing movement along said body portion whereby to contract into tight gripping engagement with said fingers when pressure is applied to the end of said sleeve by abutment with a corresponding sleeve of the second connector to thereby assure firm contacting engagement of the fingers and to provide in effeet a continuous insulation for the joined connectors.

EDWARD W. VARNUM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,731,297 Del Mar Oct. 15, 1929 2,065,315 Keath Dec. 22, 1936 2,117,029 Larsson May 10, 1938 2,127,544 Von Holtz Aug. 23, 1938 2,136,848 Hassler Nov. 15, 1938 2,335,843 Rogoif Nov. 30, 1943 2,386,177 Andersen Oct. 9, 1945 

